Consumers associate certain aromas with certain products. If the product lacks the aroma associated with it, consumer perception of the product is adversely affected. This is particularly a problem in the field of soluble beverages such as soluble coffee powder, although it also exists in other fields. For ease of description, the problem is described in this specification primarily with reference to soluble coffee powder, although the invention is not limited to soluble coffee powders. It is equally applicable to other beverage powders such as roast and ground coffee powders, soluble tea powders, soluble creamer powders, cereal-based beverage powders, and soluble chocolate powders.
Soluble coffee powders which are obtained from commercial processes involving extraction, concentration and drying, are usually substantially aroma-less. For this reason, it is conventional to trap coffee aromas which are given off during the processing of the soluble coffee powder and to reincorporate these aromas into the soluble coffee powder.
Usually the aroma is reincorporated by first capturing the aroma into a substrate such as an oil or emulsion. The aroma-containing substrate is then sprayed or plated on the soluble coffee powder prior to handling and blending. The blended coffee powders are later filled into containers which are then sealed.
A typical procedure by which an aroma-containing substrate is sprayed on soluble coffee powder is described in U.S. Pat. No. 3,148,070 (Mishkin) and Sivetz, M. and Desrosier, N.W.; 1979; Coffee Technology, AVI Publishing Company, Inc.; Westport, Conn.; pages 459 and 460. In this procedure, soluble coffee powder falls down a supply tube and onto a conical distributor which causes the soluble coffee powder to continue its fall in the form of a tubular curtain. A spray nozzle is positioned beneath the conical distributor, within the tubular curtain, to spray an aroma-containing substrate on the inner surfaces of the tubular curtain. The tubular curtain of soluble coffee powder then drops into a blender where it is mixed to homogeneously distribute the aroma-containing substrate throughout the soluble coffee powder. The aromatized soluble coffee powder is then fed into a filler machine in which it is fed into jars or other containers.
In variations of this theme, the aroma-containing substrate is sprayed on falling sheet-like curtains of soluble coffee powder or is sprayed on soluble coffee powder in tumblers, or is sprayed on soluble coffee powders transported on conveyors. In all cases, the soluble coffee powder is then run through a blender or mixer to have the aroma-containing substrate blended homogeneously throughout the soluble coffee powder.
Although this basic procedure works well, significant amounts of aroma are lost during mixing or blending of the soluble coffee powder after spraying. Further, aroma is lost during the period between spraying and filling of the coffee into containers. Also, it is found that the force of the spray causes the aroma-containing substrate to pierce the tubular or sheet-like curtain of soluble coffee powder. This results in further losses. Aroma is an expensive component and these losses can significantly increase costs. Moreover, especially for the sheet-like curtains, it is found that the aroma-containing substrate contacts only about 15% to about 30% of the curtain leading to a coffee product which is not homogeneous.
One attempt to solve the wastage problem is described in U.S. Pat. No. 3,769,032 (Lubsen). Here coffee jars, which have already been filled with soluble coffee powder, are transported to beneath a mechanical syringe which contains coffee aroma. The syringe descends into each jar until the needle tip is near the bottom of the jar. The syringe then rises and at the same time injects droplets of coffee aroma into the coffee product in the jar. The droplets have a size of about 0.5 mm to 3 mm. Although the results reported in the patent indicate good re-incorporation of the coffee aroma, the system would not be not feasible in a high-speed production line. Also, the aroma-containing substrate is not distributed homogeneously throughout the soluble coffee powder in the jar. This is significant draw-back.
Another attempt is disclosed in U.S. Pat. No. 4,355,571 (Stoeckli). This patent discloses the use of an aromatizing apparatus in which an aroma-containing substrate is plated on soluble coffee powder. A small portion of the soluble coffee powder is directed to the aromatizing apparatus and falls down a chute onto a rotating wheel. The wheel has several circumferential grooves in its surface into which the soluble coffee powder is pressed. The soluble coffee powder is rotated with the wheel through an arc of about 90.degree. after which it is expelled from the wheel. Needles are positioned immediately after the point of expulsion to inject a stream of an aroma-containing substrate on the soluble coffee powder expelled from the wheel. The aromatized soluble coffee powder is then returned to the major portion of the soluble coffee powder and blended in with the major portion. The blend is then fed to a filler machine in the usual manner.
Although the process described in this patent does not require spraying of the aroma-containing substrate, it does require blending after addition of the aroma-containing substrate. Due to the volatile nature of aroma, significant aroma losses still occur during blending and during the period between blending and filling of the coffee into containers. Also, precisely because there is no spraying, the soluble coffee powder contains large droplets of aroma-containing substrate and the aroma-containing substrate is poorly distributed.
Therefore there is still a need for a process of incorporating an aroma-containing substrate into beverage powder which results in relatively low losses of aroma.